/**CFile***********************************************************************
FileName [cuddSign.c]
PackageName [cudd]
Synopsis [Computation of signatures]
Description [External procedures included in this module:
<ul>
<li> Cudd_CofMinterm();
</ul>
Static procedures included in this module:
<ul>
<li> ddCofMintermAux()
</ul>
]
Author [Fabio Somenzi]
Copyright [This file was created at the University of Colorado at
Boulder. The University of Colorado at Boulder makes no warranty
about the suitability of this software for any purpose. It is
presented on an AS IS basis.]
******************************************************************************/
#include "util_hack.h"
#include "cuddInt.h"
/*---------------------------------------------------------------------------*/
/* Constant declarations */
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
/* Stucture declarations */
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
/* Type declarations */
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
/* Variable declarations */
/*---------------------------------------------------------------------------*/
#ifndef lint
static char rcsid[] DD_UNUSED = "$Id: cuddSign.c,v 1.1.1.1 2003/02/24 22:23:53 wjiang Exp $";
#endif
static int size;
#ifdef DD_STATS
static int num_calls; /* should equal 2n-1 (n is the # of nodes) */
static int table_mem;
#endif
/*---------------------------------------------------------------------------*/
/* Macro declarations */
/*---------------------------------------------------------------------------*/
/**AutomaticStart*************************************************************/
/*---------------------------------------------------------------------------*/
/* Static function prototypes */
/*---------------------------------------------------------------------------*/
static double * ddCofMintermAux ARGS((DdManager *dd, DdNode *node, st_table *table));
/**AutomaticEnd***************************************************************/
/*---------------------------------------------------------------------------*/
/* Definition of exported functions */
/*---------------------------------------------------------------------------*/
/**Function********************************************************************
Synopsis [Computes the fraction of minterms in the on-set of all the
positive cofactors of a BDD or ADD.]
Description [Computes the fraction of minterms in the on-set of all
the positive cofactors of DD. Returns the pointer to an array of
doubles if successful; NULL otherwise. The array hs as many
positions as there are BDD variables in the manager plus one. The
last position of the array contains the fraction of the minterms in
the ON-set of the function represented by the BDD or ADD. The other
positions of the array hold the variable signatures.]
SideEffects [None]
******************************************************************************/
double *
Cudd_CofMinterm(
DdManager * dd,
DdNode * node)
{
st_table *table;
double *values;
double *result = NULL;
int i, firstLevel;
#ifdef DD_STATS
long startTime;
startTime = util_cpu_time();
num_calls = 0;
table_mem = sizeof(st_table);
#endif
table = st_init_table(st_ptrcmp, st_ptrhash);
if (table == NULL) {
(void) fprintf(dd->err,
"out-of-memory, couldn't measure DD cofactors.\n");
dd->errorCode = CUDD_MEMORY_OUT;
return(NULL);
}
size = dd->size;
values = ddCofMintermAux(dd, node, table);
if (values != NULL) {
result = ABC_ALLOC(double,size + 1);
if (result != NULL) {
#ifdef DD_STATS
table_mem += (size + 1) * sizeof(double);
#endif
if (Cudd_IsConstant(node))
firstLevel = 1;
else
firstLevel = cuddI(dd,Cudd_Regular(node)->index);
for (i = 0; i < size; i++) {
if (i >= cuddI(dd,Cudd_Regular(node)->index)) {
result[dd->invperm[i]] = values[i - firstLevel];
} else {
result[dd->invperm[i]] = values[size - firstLevel];
}
}
result[size] = values[size - firstLevel];
} else {
dd->errorCode = CUDD_MEMORY_OUT;
}
}
#ifdef DD_STATS
table_mem += table->num_bins * sizeof(st_table_entry *);
#endif
if (Cudd_Regular(node)->ref == 1) ABC_FREE(values);
st_foreach(table, cuddStCountfree, NULL);
st_free_table(table);
#ifdef DD_STATS
(void) fprintf(dd->out,"Number of calls: %d\tTable memory: %d bytes\n",
num_calls, table_mem);
(void) fprintf(dd->out,"Time to compute measures: %s\n",
util_print_time(util_cpu_time() - startTime));
#endif
if (result == NULL) {
(void) fprintf(dd->out,
"out-of-memory, couldn't measure DD cofactors.\n");
dd->errorCode = CUDD_MEMORY_OUT;
}
return(result);
} /* end of Cudd_CofMinterm */
/*---------------------------------------------------------------------------*/
/* Definition of internal functions */
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
/* Definition of static functions */
/*---------------------------------------------------------------------------*/
/**Function********************************************************************
Synopsis [Recursive Step for Cudd_CofMinterm function.]
Description [Traverses the DD node and computes the fraction of
minterms in the on-set of all positive cofactors simultaneously.
It allocates an array with two more entries than there are
variables below the one labeling the node. One extra entry (the
first in the array) is for the variable labeling the node. The other
entry (the last one in the array) holds the fraction of minterms of
the function rooted at node. Each other entry holds the value for
one cofactor. The array is put in a symbol table, to avoid repeated
computation, and its address is returned by the procedure, for use
by the caller. Returns a pointer to the array of cofactor measures.]
SideEffects [None]
SeeAlso []
******************************************************************************/
static double *
ddCofMintermAux(
DdManager * dd,
DdNode * node,
st_table * table)
{
DdNode *N; /* regular version of node */
DdNode *Nv, *Nnv;
double *values;
double *valuesT, *valuesE;
int i;
int localSize, localSizeT, localSizeE;
double vT, vE;
statLine(dd);
#ifdef DD_STATS
num_calls++;
#endif
if (st_lookup(table, (char *) node, (char **) &values)) {
return(values);
}
N = Cudd_Regular(node);
if (cuddIsConstant(N)) {
localSize = 1;
} else {
localSize = size - cuddI(dd,N->index) + 1;
}
values = ABC_ALLOC(double, localSize);
if (values == NULL) {
dd->errorCode = CUDD_MEMORY_OUT;
return(NULL);
}
if (cuddIsConstant(N)) {
if (node == DD_ZERO(dd) || node == Cudd_Not(DD_ONE(dd))) {
values[0] = 0.0;
} else {
values[0] = 1.0;
}
} else {
Nv = Cudd_NotCond(cuddT(N),N!=node);
Nnv = Cudd_NotCond(cuddE(N),N!=node);
valuesT = ddCofMintermAux(dd, Nv, table);
if (valuesT == NULL) return(NULL);
valuesE = ddCofMintermAux(dd, Nnv, table);
if (valuesE == NULL) return(NULL);
if (Cudd_IsConstant(Nv)) {
localSizeT = 1;
} else {
localSizeT = size - cuddI(dd,Cudd_Regular(Nv)->index) + 1;
}
if (Cudd_IsConstant(Nnv)) {
localSizeE = 1;
} else {
localSizeE = size - cuddI(dd,Cudd_Regular(Nnv)->index) + 1;
}
values[0] = valuesT[localSizeT - 1];
for (i = 1; i < localSize; i++) {
if (i >= cuddI(dd,Cudd_Regular(Nv)->index) - cuddI(dd,N->index)) {
vT = valuesT[i - cuddI(dd,Cudd_Regular(Nv)->index) +
cuddI(dd,N->index)];
} else {
vT = valuesT[localSizeT - 1];
}
if (i >= cuddI(dd,Cudd_Regular(Nnv)->index) - cuddI(dd,N->index)) {
vE = valuesE[i - cuddI(dd,Cudd_Regular(Nnv)->index) +
cuddI(dd,N->index)];
} else {
vE = valuesE[localSizeE - 1];
}
values[i] = (vT + vE) / 2.0;
}
if (Cudd_Regular(Nv)->ref == 1) ABC_FREE(valuesT);
if (Cudd_Regular(Nnv)->ref == 1) ABC_FREE(valuesE);
}
if (N->ref > 1) {
if (st_add_direct(table, (char *) node, (char *) values) == ST_OUT_OF_MEM) {
ABC_FREE(values);
return(NULL);
}
#ifdef DD_STATS
table_mem += localSize * sizeof(double) + sizeof(st_table_entry);
#endif
}
return(values);
} /* end of ddCofMintermAux */